Effects of lake mixing with an axial flow pump on water chemistry and phytoplankton

Abstract

This paper describes the effect of total lake mixing with an axial flow (Garton) pump on the limnology and phytoplankton of two Oklahoma lakes .The Garton pump destratified Ham's Lake (4o ha) in 3 days . Except for one small isolated basin, Ham's Lake remained completely destratified for the rest of the summer . Algal biomass declined, numbers of species of green algae increased, but numbers of species of blue-green algae did not decrease as expected . After destratification, pH remained high (> 8), carbonate alkalinity was observed and reactive phosphate was undetectable .An axial flow pump increased the heat content of Arbuckle Lake (951 ha) and caused the lake to destratify about one month earlier than usual . Increasing the heat content of the lake did not affect the concentration of most water quality parameters or the biomass of algae .

Water chemistry changes during artificial aeration of spruce Knob Lake, West Virginia

“…, to September, 1975 3 .5 m but did not bring about destratification . Other investigators have also observed an increase in bottom water temperatures during artificial aeration (Bernhardt, 1967 ;Fast et al, 1973 ;Toetz, 1977) . Wirth et al (1975) were able to aerate the hypolimnion of two small lakes in Wisconsin without destroying thermal stratification .…”

“…During summer aeration of the hypolimnion of Larson Lake, Smith et al (1975) found no change in either total alkalinity or pH . Toetz (1977) indicated artificial aeration of Arbuckle Lake significantly lowered total alkalinity in the hypolimnion . Fast et al (1973) observed a decrease in total alkalinity in the hypolimnion of Hemlock Lake during artificial aeration, concurrent with an increase in pH attributed to the loss of CO2 via the aerator .…”

“…Of these two techniques, destratification has been used most often in artificial aeration studies (Dunst et al, 1974). Recent emphasis on improving water quality without causing destratification, in an attempt to reduce the effects of cultural eutrophication, has led to an increase in hypolimnetic aeration research (Fast et al, 1973(Fast et al, , 1975Bengtsson & Gelin, 1975 ;Smith et al, 1 975 ;Wirth et al, 1975 ;Garrel et al ., 1977 ;Toetz, 1977) .…”

“…Aeration will have the greatest impact on the phosphorus budget of a lake or reservoir when internal loading is significant (Bengtsson & Gelin, 1975) . Even though recent hypolimnetic aeration research has documented changes in several chemical parameters, including phosphorus, investigators have had either no pre-aeration data (Garrell et a!., 1977) or only one year of aeration data (Fast et al, 1973 ;Bengtsson & Gelin, 1975 ;Smith et al, 1975 ;Toetz, 1977) . Data presented by Schindler & Fee (1974) demonstrate that experiments with the nutrient regime of a lake, for example artificial aeration, should be documented over several years .…”

Artificial mixing to control cyanobacterial blooms: a review

“…A shift from cyanobacteria to green algae and/or diatoms is often found in artificially mixed lakes (Table 1; Haynes 1973;Toetz 1977;Cowell et al 1987;Steinberg and Zimmermann 1988;Hawkins and Griffiths 1993;Visser et al 1996b;Heo and Kim 2004;Huisman et al 2004;Becker et al 2006;Lehman 2014). A decrease in cyanobacterial dominance can be understood when the conditions resulting from artificial mixing of a lake are compared with the physical requirements for cyanobacterial dominance.…”